Electric railway.



L. H. THULLEN.

ELECTRIC RAILWAY.

APPLICATION FILED MAY 2p, 1905.

1,094,494, Patented Apr. 28, 1914.

rent o' the track circuit and pole of the source G to points at or nearthe centers of the said cross bonds.

In Fig. 2 a supplementary return conductor 'F is shown such as isfrequently einployecl to carry part of the return propulsion currentload which would otherwise be carried entirely by the track rails. Thissupplementary return conductor may be in the forni of a copper wire orcable laid or strung along the track or it may be an iron or steelstructure upon which the track is laid or any other suitable conductor.At L, lf, etc. I have shown my method of connecting this supplementaryreturn track rails so tor with the said rails for the return current,and it will be seen that, as in the case of cross connections betweentracks in Fig. 1, I here make my connections to points at or near thecenters of the inductive cross bonds c, c, c?, etc. thereby avoiding thedanger of short circuit-ing the track rails as regards thc alternatingcurrent flowing therein, but at the same time allowing a free path oflow ohinic resistanqp for the propulsion current.

As here shown, the alternating si naling current for the track sectionsis supp ied by an alternating current generatpr 6 which is connectedwith ing along the trackway. At cach ji'inction of adjacent sectionsl lprovide a transformer 7 the primary of which is connected with I connectthe the signaling mains and the secondary with; As shown 1n the rails ofa track section. Fig. l., each ot' these transformers comprises twosccondaries one of which is connected with the rails of a section oftrack T and the other of which is connected with the rails of a sectionof track T1. In Fig. 2 each transformer comprises only one secondary forthe reason that only one track is here shown. `Each track section isalso provided with a suitable relay 8 which is responsive to thealternating signaling current. llach relay controls a railway signal 9tor the corresponding track section by means of a local circuit in theusual and well known manner.

Cl a im 1, An electric railway having two or more tracks and in whichboth rails of cach track are used as a return for the propulsioncurrent. in combination with cross bonds having a high impedance to asignaling current and a low ohmic resistance to a propulsion current.and means for electrically connecting tho cross bonds ot' one track tothe cross bonds of one or more adjacent tracks.

Q. An electric railway having two or more tracks and in which one orboth rails of each track arc. used as a return for "ie propulsioncui-rent. in combination with rail bonds having high impedance to asignaling current signaling mains 5 Yextendg and low ohmic resistance toa propulsion current, and means for electrically connecting the railbonds of one track to the rail bonds of one or more adjacent tracks.

3. In combination, an electric railway having two or more tracks, aplurality of block sections for each track, track circuits for the blocksections, a source of propulsion current and a source o signalingcurrent, inductive bonds cunnccted across the rails of each blockadjacent the ends thereof and having high impedancil for signalingcurrent an( low impedance for propulsion current, an electric connectionfrom one bond to the adjacent bond, and an electric connection from apair of bonds on one track to a pair of bonds on an adjacent track.

4. In an electric railway two or more tracks, a plurality of inductivecross bonds for each track, each cross bond connectin one rail of itstrack to the opposite rail, an a -plurality of electric bonds connectingone or more cross bonds of one track to one or more. cross bonds on eachof the other tracks of the railway.

5. In an electric railway, a source of propulsion current, an inductivecross bond having high impedance to a signaling current and low ohmicresistance to a propulsion current connecting the rails on one side ofductor of the propulsion current.

6. In a signaling system of the type described, a plurality of pairs ofparallel lines of rails included in the circuit of the propulsioncurrent, means for cross-connecting said parallel lines of rails, saidmeans comprising a conductor connected to one rail of each pair of railsand a conductor connected to one rail of cach pair of rails throughreactance bonds. i

In a signaling system of the type described, a plurality of pairs ofparallel lines of rails included in the circuit of the propulsioncurrent, means for cross-connecting said parallel lines of rails, saidmeans comprising a conductor connected to one rail of each pair of railsand a conductor connected to one rail of cach pair of rails throughdevices which will obstruct the flow of an alternating current.

8. In combination, an electric railway having two or more tracks therails of which arc included in the circuit for the propulsion current,an inductive bond for each track connected across the rails of thetrack, and a conductor connectingr substantially the middle point of thewinding of the bond for one track with substantially they middle pointof the winding of the bond for another l track.

9. In combination, having n plurality of xsections for each track .ormedby insulations in hath lines of rails, inductive bonds connected acrossthe rails of each block adjacent the ends of the block, a, conductorconncctin substantially the middle oint of each bong with substantiallythe nnddle point cf the adjacent bond for the adjacent block section, l

an electric railwav arallel tracks, block and an electrical connectionbetween a conductor for one track and a smnlar conductor for anothertrack.

In testimony whereof I have signed my 16 name to this specification inthe presence of two subscribed witnesses.

